Role of TGFbeta in Microtubule Dynamics

TGFbeta 在微管动力学中的作用

• 批准号: 7915833
• 负责人: Kathleen M Mulder
• 金额: $ 34.93万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7915833
• 关键词: Affect; Antineoplastic Agents; Arts; Back; Binding; Biological; Cancer Patient; Cell Cycle Inhibition; Cell Cycle Progression; Cell Nucleus; Cells; Characteristics; Complex; Cyclic AMP-Dependent Protein Kinases; DNA Synthesis Inhibition; DNA biosynthesis; Data; Defect; Development; Disease; Dyes; Dynein ATPase; Early Endosome; Endocytosis; Endosomes; Event; Family; Fibronectins; Figs - dietary; Future; Gene Targeting; Goat; Growth Factor; Human; Image; Immunoglobulin G; Impairment; In Vitro; Incubated; Intracellular Transport; Investigation; Left; Ligand Binding; Light; Link; MDCK cell; Malignant Neoplasms; Malignant neoplasm of ovary; Mediating; Microscope; Microscopy; Microtubules; Modeling; Motor; Mus; Mutate; Mutation; Nature; Normal tissue morphology; Nuclear; Nuclear Translocation; Organelles; Oryctolagus cuniculus; Pathway interactions; Phosphorylation; Phosphorylation Site; Phosphotransferases; Plasmids; Play; Preparation; Protein Isoforms; Proteins; Recruitment Activity; Regulation; Reporting; Resistance; Role; Serum; Signal Transduction; Signaling Molecule; Small Interfering RNA; Specific qualifier value; Specificity; Students; System; Testing; Thymidine; Time; Tissues; Transcriptional Regulation; Transfection; Transforming Growth Factor beta; Transmembrane Transport; Transport Vesicles; Vesicle; Western Blotting; base; cancer cell; cell growth; drug development; dynein light chain; functional outcomes; in vivo; innovation; knock-down; malignant phenotype; member; mutant; neoplastic cell; novel; oncology; receptor; research study; response; trafficking; tumor; tumor progression

DESCRIPTION (provided by applicant): A higher order of regulation can be achieved by compartmentalization and functional specialization of the endocytic pathway during signal transduction in response to growth factors (GFs). In contrast, impairment of intracellular (IC) trafficking of GF signaling complexes can result in mis-localization or accumulation of signaling molecules in the wrong compartment, or at the wrong time, giving rise to various disease states, including cancer. In addition, the specificity of motor protein light chains (LCs) in recruiting their membranous cargo for IC transport during regulation of GF signaling is becoming increasingly clear. Additional investigation of the regulation, key components, timing, and functional outcome of signaling from endosomal subcompartments is required to enable oncology drug development, based upon these newer signaling regimes. Our data from the last project period indicated that km23 dynein LCs are activated by TGF? receptors (T?Rs) and are required for Smad trafficking, prior to nuclear translocation. Thus, km23 appears to function as a "motor receptor" to recruit TGF? signaling complexes to the dynein motor for IC transport of cargo (ie, T?Rs, Smads) along microtubules (MTs) toward the nucleus. In addition, we have identified another related member of the km23/LC7/robl/DYNLRB family, termed km23-2. While this isoform appears to have some characteristics similar to km23-1, km23-2 appears to more specifically regulate Smad3, in contrast to Smad2 regulation by km23-1. The mechanisms underlying the differential regulation and trafficking of Smads2/3 in relation to the km23-1/2 motor LCs will be explored in the new application, including how km23 impacts downstream TGF? responses. During the last project period, we have also shown that protein kinase A (PKA) directly phosphorylates km23 and is required for km23 binding to the dynein intermediate chain (DIC). The mechanisms underlying this PKA phosphorylation of km23 in TGF? signaling and Smad2/3 trafficking will also be examined. Additional studies relate to the investigation of how these trafficking events are altered in human ovarian cancer cells (HOCCs) known to express altered forms of km23-1. As part of the last project period, we identified km23-1 alterations in 42% of ovarian cancer patient tissues, with no km23 alterations detectable in normal tissues. Such a high alteration rate in ovarian cancer suggests that km23 may play an important role in either TGF2 resistance or tumor progression of this disease. In the new application, we will examine the effects of knocking down km23, or mutating it at key phosphorylation sites, on Smad trafficking, Smad-specific TGF? responses, and the malignant phenotype of the human cancer cells in vitro, as well as on tumor progression in vivo.

描述（由申请人提供）：在响应生长因子（GF）的信号转导过程中，通过胞吞途径的区室化和功能特化可以实现更高级别的调节。相反，GF信号传导复合物的细胞内（IC）运输的损伤可导致信号传导分子在错误的区室中或在错误的时间错误定位或积累，从而引起各种疾病状态，包括癌症。此外，马达蛋白轻链（LC）在GF信号调节期间招募其膜货物用于IC转运的特异性正变得越来越清楚。需要对来自内体亚区室的信号传导的调节、关键组分、时机和功能结果进行额外的研究，以基于这些更新的信号传导机制来实现肿瘤药物开发。 我们的数据从最后一个项目期间表明，km 23动力蛋白LC激活TGF？受体（T？Rs），并且在核易位之前是Smad运输所需的。因此，km 23似乎作为一个“运动受体”招募TGF？信号复合物的动力蛋白马达IC运输货物（即，T？Rs、Smads）沿着微管（MT）向细胞核移动。此外，我们还鉴定了km 23/LC 7/robl/DYNLRB家族的另一个相关成员，称为km 23 -2。虽然这种亚型似乎具有一些类似于km 23 -1的特征，但km 23 -2似乎更特异性地调节Smad 3，而不是通过km 23 -1调节Smad 2。在新的应用程序中，将探讨Smads 23相对于km 23 -1/2马达LC的差异调节和贩运的机制，包括km 23如何影响下游TGF？应答在上一个项目期间，我们还表明，蛋白激酶A（PKA）直接磷酸化km 23，是km 23结合动力蛋白中间链（DIC）所必需的。PKA磷酸化km 23在TGF？还将检查信号传导和Smad 2/3贩运。 其他研究涉及调查这些运输事件如何在已知表达改变形式的km 23 -1的人卵巢癌细胞（HOCC）中改变。作为上一个项目的一部分，我们在42%的卵巢癌患者组织中发现了km 23 -1的改变，而在正常组织中没有检测到km 23的改变。卵巢癌中如此高的改变率表明，km 23可能在TGF 2抵抗或这种疾病的肿瘤进展中起重要作用。在新的应用程序中，我们将研究敲低km 23，或在关键磷酸化位点突变，对Smad贩运，Smad特异性TGF？反应和体外人癌细胞的恶性表型，以及体内肿瘤进展。